A radio transceiver is typically constructed using building blocks that implement receiver functions, transmitter functions, and audio processing functions, among others. Generally, these radio building blocks are implemented using multiple circuits, some having a high degree of integration. There has been a substantial effort to reduce the size and cost of radio transceivers. In this effort, significant portions of radio circuits have been integrated, and made available as custom chip sets which perform a particular function. Custom chip sets allow a radio designer to take advantage of the substantial cost savings available when the chip sets are mass produced. However, such cost savings tend to come at the price of flexibility in that the circuits are not easily changed without incurring a substantial cost in the design and manufacture of new custom chips. For example, if some circuits are satisfactory while others are not, a redesign of the custom chip is typically necessary.
There has been a desire to integrate as many functions as feasible on a single integrated circuit when implementing a radio transceiver. An entire transceiver system integrated on a common substrate would tend to reduce cost and increase reliability. However, difficulty in designing and integrating appropriate circuits has limited practical implementations. Preferably, an integrated transceiver system should be designed to allow for some flexibility in improving performance and functionality. Therefore, a configurable single-chip radio transceiver is needed.